The present invention relates to an automotive vehicle seat assembly and in particular to a seat assembly in which the seat cushion frame and the seat track frame are integrated into a single load carrying structure.
A vehicle seat assembly is typically constructed with a seat track frame that comprises, along each side of the seat assembly, a fixed rail that is mounted to the floor pan of a motor vehicle, a slide rail slidably carried fore and aft upon the fixed rail and a riser extending upwardly from the slide rail. A seat cushion frame is mounted to the risers, and serves as the support structure for the seat cushion of the seat assembly. Extending upwardly from a rear portion of the riser is a seat back frame which supports the seat back of the seat assembly.
The seat cushion frame is typically constructed of a pair of fore and aft extending side members along each side, a front cross member extending laterally between and connected to the front ends of the two side members and a rear cross member extending laterally between and connected to the rear ends of the two side members. A flexible wire seat cushion suspension extends laterally between the two side members to support a foam seat cushion pad. When the seat is occupied, the weight of the occupant produces a vertical load applied to the seat cushion suspension. This vertical load is transferred from the suspension to the side members and then to the risers in the seat track frame from where it is distributed to the floor pan of the vehicle.
The seat cushion suspension, in transferring the vertical load to the side members also creates a substantial lateral force on the side members, directed inwardly tending to urge the two side members of the cushion frame toward one another. The front and rear cross members operate to resist the lateral load without transferring the lateral load to the seat track frame. Only the vertical load is transferred to the seat track frame.
Due to a continuing desire to reduce the weight of motor vehicles, it is an object of the present invention to reduce the weight of the seat cushion frame without compromising its structural integrity.
It is a feature of the present invention that the seat cushion frame is integrated with the seat track frame, enabling the lateral suspension load to be carried by the seat track frame as well as the vertical load. This load transfer enables the rear cross member to be deleted from the seat cushion frame, thus reducing the weight of the seat cushion frame. Since the seat track frame is a structural member already designed to accommodate high loading, little, if any, reinforcement is required in the seat track frame to accommodate the lateral suspension load. Any weight increase in the seat track frame is small in comparison to the weight reduction by eliminating the rear cross member from the seat cushion frame. The total weight reduction is approximately 20 percent of the seat cushion frame weight.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.